Moisture stratified substrate

[K Smith]

Does any one else use this method of keeping humidity levels high? I found it after reading Jacobi's new book and it seems to be working great. Just by running water down one cage wall so that the lower level is fairly damp while the upper inch or so is barely moist. Therefore making layers of substrate of varying dampness (moisture stratified).

'Moisture from the bottom of the substrate will evaporate over time and increase humidity without causing the ground that the tarantula lives on to become wet'

I've found that this method reduces the risk of mites and also creates a more stable humidity and less maintainence.

I also use the evaporation from the water dish and partially cover the lid to keep humidity levels stable. Of course this method is adjusted for the particular species requirements.


Just wondering if anyone else has/does use this method and your opinions of it? In my opinion, I have found that it does create a more stable humidity and less maintainence, and creates a cleaner environment for the spider as the substrate is not constantly soaked from the top down. The top layer is always dry preventing mites or fungus.

I even used it as a way of giving my Pelinobius muticus water by running water down the side of the tank, then it soaked through the substrate and dripped onto the floor of her burrow giving her a drink before it evaporates. Good as she always tips her water dish up and uses the dish as a cover for her burrow. Everytime I fill the dish she comes out and does it, but i've never actually seen her out of her burrow and im in that spider room A LOT.

Hope to hear of your thoughts of this

[Peter Roach]

Ive been doing the exact same thing for years. I've never worked out why most people spray or mist their T's, which as we all know (or should) only wets the top few mm of the substrate.

[K Smith]

Thanks for the reply Peter. It's reassuring to know someone with experience is using the same method. That's what I wanted to find out. When I first started keeping tarantulas I used to wet the substrate and mist, but the mist evaporated within minutes to hours and the damp substrate just encouraged mite and fungus growth. This method seems perfect as the top inch or so is dry as a bone but the lower layers are damp enough to allow gradual evaporation thus a stable humidity, and less annoying the spider with spraying and maintainence.

Happy spider, Happier hobbyist

[Mark Pajak]

I use a layer of cat litter at the bottom to act as a humidity buffer - absorbing excess moisture whilst releasing moisture to dry air. Not all cat litter is good though - non clumping red clay granules are best.